1. Field of the Invention
This invention relates, generally, to toner cartridges. More particularly, it relates to a toner cartridge that fits a large plurality of printers of differing brands and models.
2. Description of the Prior Art
Printer manufacturers such as IBM, Lexmark, and the like also make the toner cartridges that fit their respective printers.
Some printer cartridges, such as those manufactured by Hewlett Packard, employ a single component design. However, most companies make a toner cartridge that includes a waste bin containing waste toner and a hopper containing the toner supply. The hopper is connected to the trailing end of the waste bin. The leading end of the waste bin is inserted into the printer first when a toner cartridge is being installed. The user holds the trailing end of the waste bin when the toner cartridge is installed and removed.
Each printer manufacturer designs its printers to accept toner cartridges manufactured by it and to reject the toner cartridges manufactured by others.
More particularly, to increase sales of their own toner cartridges, printer manufacturers have added structural features to the printers and to the toner cartridges that do not enhance the functional performance of the printer in any way but which serve to prevent use of a competitor's toner cartridge in the printer.
Printer manufacturers also prefer to sell new toner cartridges to replace empty toner cartridges. Therefore, they do not support the re-cycling industry.
Thus there is a need for a universal adapter that enables a single toner cartridge to be used with printers made by differing manufacturers and with differing printer models made by a common manufacturer. Such a universal adapter could be re-filled with toner when empty by the re-cycling industry.
The waste bin and hopper in conventional toner cartridges are pivotally interconnected to one another so that the hopper may move up and down in a vertical plane while the waste bin is secured into an immovable position. A full hopper has a weight sufficient to prevent it from pivotal movement, but as the hopper grows lighter as the toner therein is consumed, the hopper pivots upwardly under the influence of biasing means positioned at its opposite ends.
The pivotal interconnection ensures that a proper nip is formed between the photoconductive drum of the waste bin and the developer roller of the hopper. Such pivotal mounting requires the use of springs to interconnect the waste bin to the hopper. It also requires use of a shipping lock strap during shipping to prevent the hopper from bouncing inside the printer or toner cartridge shipping box during transportation.
There are several drawbacks to a pivotal interconnection of a waste bin and a hopper. The most obvious drawback is the need for an elongate spring at each end of the toner cartridge. A first end of each spring must be secured to the waste bin and a second end thereof must be secured to the hopper. This makes the assembly of the toner cartridge more difficult and increases the time required to complete the assembly. Moreover, during remanufacturing of the toner cartridge, additional handling of the spring can cause the loss of necessary spring tension causing improper nip between the developer roller and the photoconductive drum.
Thus there is a need for an improved means for interconnecting a waste bin and a hopper. The improved interconnecting means should eliminate the pivotal mounting of the toner cartridge within the printer, eliminate the springs, and eliminate the need to use a shipping strap during transportation of the cartridge.
If the toner hopper and waste bin are not pivotally connected to one another, a new construction is required for holding the hopper and waste bin together.
The new construction must ensure that a proper nip is formed between the photoconductive drum that forms a part of the waste bin and the developer roller that forms a part of the hopper.
To insert a toner cartridge into a printer, the leading end of the waste bin is introduced into a waste bin-receiving cavity formed in the printer. A laterally extending wing, usually called a planar wing, is formed integrally with each side wall of the waste bin and is slidingly received within guide grooves formed on opposite sides of the waste bin-receiving cavity formed in the printer body.
The known planar wings are thin at their respective leading ends so that they can more easily enter into the guide grooves of the printer and thick at their respective trailing ends to provide more structural integrity. The leading ends are thus somewhat fragile and can be broken if a user does not exercise care when inserting a toner cartridge into a printer.
Thus there is a need for an improved, more robust planar wing design having a uniform thickness along its extent so that the leading end thereof is no thinner than the trailing end thereof. The more robust planar shape also improves installation and removal of the toner cartridge into and out of the printer.
A conventional waste bin may include a small circuit board that, if present, must enter into electrical communication with electrical contacts on the printer to activate the printer. More particularly, one or more connection pads are mounted on the circuit board. Electrical contacts mounted on the printer at a preselected location, such as a printer door, communicate electrically with said circuit board through said connection pads.
This invention also includes optical communication means that may replace any electrical communication means mentioned herein.
Some waste bins have a small, substantially horizontally-disposed mounting pad on a left edge of a top wall thereof that supports the circuit board that is aligned to mate with (through the aforementioned connection pads) the electrical contacts secured to an associated printer. Other waste bins have a small mounting pad just to the right of the left edge-mounted pad to mate with the electrical contacts of other printers. Still other waste bins have a small, vertically disposed mounting pad on a front wall of the waste bin.
Thus there is a need for a waste bin having both horizontally and vertically mounted pads that accommodate the circuit boards of all waste bins and which are positioned so that said circuit boards are properly positioned for electrical communication with the electrical contacts of the printer with which the waste bin is used. Such a waste bin does not appear in the prior art.
Conventional printers further include a microswitch that enables the printer to operate when its cartridge door is fully closed. More particularly, when the cartridge door is fully closed, it engages a door-closed microswitch-actuating tab having a thin, upstanding construction. As a printer ages, its hinges and latches become worn to the extent that the cartridge door no longer engages the actuating tab even when the cartridge door is fully closed. The microswitch is therefore not closed and no “door closed” signal is sent to activate the printer.
Thus there is a need for an improved tab that is engaged by a closed cartridge door even when the hinges and latches of a printer door have become worn. More particularly, when the hinges and latches of a printer door have become worn, the needed tab would act to better position the closing of the door by centering on the microswitch port.
Conventional toner cartridges are also difficult to insert into a printer. No dedicated gripping surface is provided so most users simply grasp the trailing end of the waste bin and hopper in a haphazard manner. The plastic on the trailing end of the waste bin has a lattice work or open mesh structure and a user is expected to place his or her fingers through various narrow slots provided by such lattice work when lifting and installing the toner cartridge. The fingers of many people cannot fit between the minimal clearance between the waste bin handle and hopper, thereby making the handling of the toner cartridge difficult. Since the cartridge has no dedicated handle, the user will most likely grasp the cartridge off center and the weight of the hopper and waste bin together will cause the toner cartridge to tilt relative to a horizontal plane as the user attempts to insert the toner cartridge into the printer. The toner cartridge often jams as a result.
Thus, there is a need for a toner cartridge with a dedicated gripping means that centers a user's hands relative to the trailing end of the toner cartridge so that it can be placed into the printer while being held in a horizontal plane. Nor should an improved handle rely on narrow slots as part of the gripping means.
Printers are also subject to jamming due to poorly designed media guides that are formed on the lower wall of the waste bin of a toner cartridge.
Accordingly, there is a need for an improved waste bin having improved media guides that reduce the frequency of paper jams.
Printers typically include downward forcing levers that bear against the toner cartridge after it has been inserted to keep the toner cartridge from rattling during printer operation. However, on the known cartridges, the levers bear against flat surfaces. Thus, if the toner cartridge is not installed properly, the levers bear against the cartridge and hold it in said improper position.
There is therefore a need for an improved design that would ensure that the toner cartridge is in its optimal position relative to the printer when the downward forcing levers of the printer engage the toner cartridge.
A toner cartridge is removed from a printer by manually lifting the trailing end of the toner cartridge relative to the stationary printer. However, in the known printer designs, very little clearance is provided for this lifting procedure, thereby increasing the degree of difficulty encountered when removing a toner cartridge. The small clearance also increases the difficulty associated with inserting a toner cartridge into a printer.
Thus there is a need for a design that increases the clearance to facilitate the introduction and removal of a toner cartridge into and from a printer, respectively.
The known toner cartridges also have a door, known as the shutter or upper shutter that is hingedly mounted to the top of the cartridge. The shutter pivots downwardly like a conventional door on a simple two pin hinge.
Thus a need is extant for an improved shutter construction.
However, in view of the prior art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in the pertinent art how the identified needs could be fulfilled.